In general, planting implements (such as planters) are towed behind a tractor or other working vehicle through a hitch attached to a rigid structure of the implement, such as a chassis. These planting implements typically include multiple row units of planting distributed across the width of the implement, wherein said planting rows may vary in number, such as from 2 to 30 planting rows, or even more. Each planting unit is configured to cut the straw, open a groove in the soil, deposit seeds at a desired depth below the soil surface, thereby establishing planted seed rows, close the opened groove and, in some models, compact the soil after closing.
Optionally, planters may also comprise a system of fertilizer deposition on the soil when a groove is opened in the soil, wherein said fertilizer deposition may be carried out together with the opening disc. Furthermore, silos or tanks to store seeds and fertilizer, as well as systems for dispensing seeds and fertilizer may be coupled to the implement rigid structure, which herein is also referred to as chassis.
Planters are agricultural implement quite known and widespread in the state of the art, which is a reason why there is no need for more detailed description herein.
The discs performing the opening (groove) in the soil to allow seed deposit—herein referred to as opening disc—is usually mounted on a suspension to accompany the irregularities of the soil and open grooves at a constant depth. Seed deposit at a constant depth with respect to the soil surface is a desirable feature because it increases the crop yield, given that the growth of the crop will be more homogeneous with respect to seeds planted at different depths.
Under certain conditions and certain soil run by the planter, it may be desirable that the opening disc (or the opening discs, considering each opening disc of each planting row) exhibits a pivotal movement with respect to a support point, that is, the disc angularly varies its height in relation to a reference point. On the other hand, for other types of soil and planting conditions, it may be desirable that the opening disc exhibits a pantograph movement, that is, that it vertically varies its height in relation to a reference point.
The currently existing problem is that the known prior art planters have only one type of suspension, either pivoting or pantographic, and if the producer wants to vary the type of movement of the opening disc depending on the varying soil conditions, for instance, it is necessary to possess a second agricultural implement already provided with a different suspension from the one of the other available implement. Alternatively, in order to avoid purchasing a second implement, the producer would have to retrofit the existing implement, which would be time-consuming and relatively onerous.
Thus, there is the need for an agricultural implement, such as a planter, allowing the suspension of the opening disc to exhibit both a pivoting (angular) and a pantographic (vertical) movement to follow the soil irregularities with no need for major changes in the implement. The invention aims to meet this need, among others.